Plug-cut-out base



R. C. COLE.

PLUG CUT-OUT BASE.

- APPLICATION FILED FEB. 27. 1919.

PatentedAug. 31, 1920.

InvE/v'far' MIC. fiVa /if Affarfls their.

ROBERT C. COLE, OF HARTFORD, CONNECTICUT, ASSIGNOR T THE JGI-INS-PRATT COMPANY, or nnnrronn, oonnnorrcur,

A CORFORATION 13F CONNECTICUT.

PLUG-CUT-OUT BASE.

Specification of Letters Patent.

Patented Aug". 31, 1920.

Application filed February 27, 1919. Serial No. 279,562.

To all whom it may concern:

Be it known that I, Bonner C. Come, a citizen of the United States, residing at Hartford, in the county of Hartford and State of Connecticut, have invented a new and useful improvement in Plug-Cut-0ut Bases, of which the following is a specification.

This invention relates to those cut-out bases which have screw-threaded shells, for receiving similar threaded ends of fuse plugs, terminal plugs, and lamps, with central contacts in the bottoms of and insulated from the shells and conducting means connected respectively with the shells and contacts for attachment to circuit wires.

The object of the invention is to provide a construction for cut-out bases of this type which allows all the live parts to be assembled and fastened from the front and which interposes a solid wall of insulation between the live parts and the surface upon which the base is mounted, eliminatingholes through the base and'doing away with the requirement of waxing counter-bores containing the heads of fastening screws on the back, thereby increasing the rapidity of assembly, effecting material saving in the cost of manufacture, and affording better protection than is possible with the bases as commonly made. 7

In the old type of bases of thischaracter the center contact screw which passes through the insulation and is fastened from the back and requires subsequent covering at the back with wax, holds the live parts together and also in place, whereas in the present improvement the terminal strips pass through openings in the insulating walls of the socket in such manner as to hold the parts in place, and the center contact screw which is turned in from the front only looks the parts together.

The invention is applicable to one, two or three pole bases, but the multiple pole devices are exactly the same as the single pole, except as to duplication of parts, a single pole device only isillustrated and described.

Figure 1 of the accompanying drawings shows a plan of a cut-out constructed according to this invention. Fig. 2 shows a central section of the same. Fig. 3 shows a plan of the insulating block and socket with the live parts omitted. Fi 4 is a view looking at one end of the insulating block and; socket. Fig. 5 is a view looking at the other end of the insulating block and socket. hlgt- 6-is a plan of one of the conducting terminal strips that is inserted through an opening in one side of the insulating block. F 1g. 7 ]S a plan of an insulating disk that is placed in the socket on top of the inner end of the aforementioned. terminal strip.

8 is a plan of the screw-tl1rea 1led metallicshell that is set in the insulating disk. 9 is a plan of the other terminal that is inserted through an opening in the other side of the block and has its inner end resting upon the bottom of the shell. Fig. 10 is a plan of an insulating disk that is placed in the shell over the inner end of the terminal shown in 9. The block 1 of these devices is usually made of porcelain with a porcelain socket 2 extending outward from the front. In the front face on one side of the socket is a recess 3 and from this recess is an opening ithrough the lower end of the wall of the socket. in the front face on the other side of the socket is a recess 5 and from this recess is an opening 6 through the lower end of the wall of the socket. In the side wall of the socket and extending outwardly from this latter opening, and narrower than the width of the opening, is a slot 7.

' The conducting terminal strip 8 which passes through the opening .4. in the base of the socket has a threaded perforation 9 at its inner end and a threaded perforation 10 at its outer end for the binding screw 11. After this terminal strip located in position a disk of insulation 12 is placed in the socket over the inner end of the ter1ninal strip, This disk has a central opening 13 that coincides with the inner threaded perforation through the terminal strip and it has a tongue 14: that projects sidewise into the opening 4 through the wall of the socket through which the terminal 8 extends. The screw-threaded metallic shell 15 is seated upon the front of this insulating disk. A portion 16 of the bottom of this shell is cut away, as is also a small section of one side. The terminal strip 17 has a forked inner end 18 and a perforation 19 at its outer end for the binding screw 20. A. section 21 of this terminal strip is wider than the width of the slot 7 in the wall of the socket upon the socket, and a section 22 is narrower than I the slot. The forked inner end of this terminal strip is arranged in the shell before the shell is put in the socket and'when the shell is placed in the socket the narrow section 22 of the terminal is passed inward through the slot. After the shell with this terminal has been located the terminal is drawn outward to one side so that its wide section 21 will pass into the opening 6beneath the walls of the socket at the inner end of the slot. vi hen in this position the terminal and shell cannot be lifted out as held in position, thus locked by the center screw, as result of the passing of the ter minal strip on each side through the openings in the side walls of the insulating socket. 7

With this construction it is unnecessary to have hole through the porcelain block for securing the parts in place, therefore, there is a solid wall of porcelain between all the live metal parts and the surface upon which the base is mounted. This, of course, eliminates the customary and required act of waxing the counter-bores which receive the heads of the screws of the old type of cut-out that hold the parts in place; result of this improvement there is a: ma terial saving in the amount of metal and other materials used, the time of assembly is lessened, and the insulating qualities of the block are increased Furthermore, the metallic shell is more completely shrouded by insulation with this construction than in the prior constructions with consequent less liability of accidental short circuiting by contact with the shell.

The invention claimed is? I 1. A plug cut-out base comprising an insulating socket having a slot in one side with an opening through the side wall into 55 the bottom of the socket at the inner end of said slot, said opening being wider than the slot, and an opening through the side wall' into the bottom of the socket on the opposite side from the slot, a threaded'metallic shell located in said socket, conducting terminal strips extending from opposite sides tlllOIlgliSitlCl openings into the socket and held from movement longitudinally out of thesocket ly the walls of said openings,

the inner end of one terminal strip being in contact with the bottom of the shell, an insulating disk-separating the inner end of the other terminal strip from the bottom of the shell, an insulating disk in the shell outside of the terminal strip that is in contact with the shell, and a screw turned in from the front through the parts and into the terminal that is insulated from the shell;

2. A plug cut-out base comprising an insulating socket having a slot in one sidewith an opening through the side wall into the bottom of the socket at the inner end of said slot, said opening being wider than the slot, and an opening through the side wall into the bottom of the socket on the opposite side from said slot, a conducting terminal strip extending through the latter opening into the bottom of the socket, an insulating disk located in the socket on the inner end of said terminal strip, a metallic threaded shell seated in the socket on said insulating disk, a conducting terminal strip extending through the opening at the lower end of said slot into the socket and engaging the bottom of the shell, an insulating disk in the shell over the inner end of the terminal strip that is engaged with the shell, and a screw turned in from the front through the parts into the inner end of the first mentioned terminal for binding the live parts together.

3. 'A plug cut-out base comprising an insulating socket having'a slot in one side with an opening through the sidewall into the bottom of the socket at one end of said slot, said opening being wider than the slot, and an opening through the side wall-into the bottom of the socket on the opposite side of said slot, a conducting terminal strip eX tending through the latter opening into the bottom of the socket, an insulating disk located in the socket on the inner end of said terminal strip and having a tongue that extends outwardly into the opening through the wall of the socket, a metallic threaded shell seated in the socket on said insulating disk, a conducting terminal strip extending through the opening at the lower end of said slot into the socket and engaging the bottom of said shell, said strip having a section that is narrower than and a section that is wider than the width of the slot in the wall of the socket, an insulating disk in the shell over the inner end of the terminal strip that is engaged with the shell, and a screw turned in from the front through the parts into the inner end of the first mentioned terminal strip for binding the live parts together.

4. A plug cut-out base comprising a single-piece insulating socket having one end .open, one endclosed and openings through the side wall at the inner end of the socket, a threaded metallic shell loose in the socket, a metallic stripextendingradially through one opening in the side wall of the socket 13( and insulated from the shell, a metallic strip extending radially through the other opening in the side wall of the socket and engaged with the shell, the latter strip being adjustable longitudinally with relation to the former strip and when in one relation enga ing the wall of the opening through which it passes and held from removal thereby, and a screw contact in the center at the inner end of the socket extending through but insulated from the shell and strip engaged therewith and turning into the insulated strip, which screw contact when tightened locks the conducting parts together with the adjustable strip in position to engage the wall of the opening through which it passes and resist any tendency to pull the parts from the socket.

5. A plug cut-out base comprising an inte gral insulating socket having a closed bottom and openings through its side wall into the bottom of the socket, a threaded metallic shell loosely located in the socket, conducting terminal strips loosely extending in recesses in the base through the openings in the side wall of the socket and retained from displacement toward the open end of the socket by the walls of said openings, one of said strips being connected with the shell and the other insulated therefrom, and conducting means extending from the center of the bottom of the socket through the shell and strip connected therewith and into said insulated strip and terminating above the bottom of the socket, whereby the shell and terminals are held together as a unit and loosely retained in the socket by the engagement of the terminal strips with the walls of the openings through which they pass.

6. A plug cut-out base comprising an iiitegral insulating socket having a closed bottom and openings through opposite sides into the socket, a threaded metallic shell loosely located in the socket, conducting terminal strips extending in recesses in the base through said openings, the inner end of one of said strips being above and in contact with the bottom of the shell and the inner end of the other of said strips being below and insulated from the bottom of said shell and a screw insulated from the shell and strip connected therewith turned in from the front through the parts into the inner end of the strip insulated from the shell and ending above the bottom of the socket, whereby the shell and terminals are held together as a unit and loosely retained in the socket by the engagement ofthe strips with the walls of the openings through which they pass.

7. A plug cut-out base comprising a sin gle-piece insulating socket and supporting base with radial openings through the side wall at the bottom of the socket, and a con ducting unit composed of a threaded metallic shell, a metallic strip extending through one opening and electrically engaged with the shell, a metallic strip extending through the other opening and insulated from the shell, and a threaded metallic contact insulated from the shell and connected strip and threaded contact.

ROBERT C. COLE screwed into the insulated strip and locking I 

